In typescript when targeting es5 the recipes above don't work (because it doesn't follow es module system in this case).
You can create a file which will pull all semantic-ui-react modules you are using one by one and reexport them. Than in your code you just bring modules from the helper file rather than from the library itself.
Like this:
import Button = require('semantic-ui-react/dist/es/elements/Button');
import Icon = require('semantic-ui-react/dist/es/elements/Icon');
import Image = require('semantic-ui-react/dist/es/elements/Image');
import Input = require('semantic-ui-react/dist/es/elements/Input');
import Label = require('semantic-ui-react/dist/es/elements/Label');
import Form = require('semantic-ui-react/dist/es/collections/Form');
import Menu = require('semantic-ui-react/dist/es/collections/Menu');
import Message = require('semantic-ui-react/dist/es/collections/Message');
import Table = require('semantic-ui-react/dist/es/collections/Table');
import Checkbox = require('semantic-ui-react/dist/es/modules/Checkbox');
import Dropdown = require('semantic-ui-react/dist/es/modules/Dropdown');
import Modal = require('semantic-ui-react/dist/es/modules/Modal');
import Confirm = require('semantic-ui-react/dist/es/addons/Confirm');
import TextArea = require('semantic-ui-react/dist/es/addons/TextArea');
import { DropdownItemProps, CheckboxProps, InputProps,
MenuItemProps, ModalProps, TextAreaProps } from 'semantic-ui-react/index.d';
export { Button, Dropdown, Confirm, Icon, Input, Modal, Label,
Table, Checkbox, TextArea, Form, Menu, Image, Message };
export { DropdownItemProps, CheckboxProps, InputProps, MenuItemProps, ModalProps, TextAreaProps };